1. Obligatory calibration
Water meters which are to be used in business traffic or are to be held ready in order to be placed on the market without preliminary preparation, have to be immediately verified.
This concerns not only water meters of utilities but also water meters owned by companies or private persons – such as apartment meters, floor meters or intermediate meters. Water meters with a maximal flow rate of at least 2.000 m³/h make an exception under certain circumstances.
The calibration of the measuring devices has to be performed by calibration authorities. Above mentioned devices are usually calibrated by state approved test centers. Such testing facilities are owned by different manufacturers of water meters or utilities.
3. Marking for the calibration
The water meters are being marked as calibrated with the so called main seal through the calibration authorities or through the public recognized testing facilities. This main seal contains the following marking:
the sign placed on the 2nd position (the indication of the year) indicates the year the calibration has been performed.
4. Calibration capability of water meters
Measuring devices to be calibrated must have a certain design which is approved for calibration.
The sign of the type approval is the approval sign on the device acc. to the following example:
For water meters that do not have a type approval apply different transitory provisions which can be inquired at the trade office.
5. Validity of calibration
The calibration has limits. Cold water meters are valid for 6 years* and warm water meters, 5 years. This means, that the water meters are subject of a new calibration as soon as this time limit has been exceeded. A special request to that does not exist. An early termination of validity may occur in case the device fails after calibration the permitted error limits because i.e. of the water quality or if the main stamp or a seal stamp has been damaged. The validity of the calibration is being prolonged for 3 years if the accuracy of the measurement is proved by a random sample testing.
6. Duties for the owners of measuring devices regarding calibration
Measuring devices have to be cleaned and properly prepared for calibration. They have to be brought to the calibration point by the owner. The calibration authorities and the public recognized testing facilities do not unmount or mount the devices at the customer site nor do they perform maintenance work.
7. Administrative offence
The deliberate or negligent usage or availability of water meters without calibration in the business traffic is an administrative offence. It can be punished with a penalty up to 5.000 €.
8. Legal ground
The legal ground of the references are to be found in the following regulations and directives:
a) Eichgesetz (calibration act) new version as of 23rd March 1992 (BGBI.IS.711) in its present version (BGBI.IS.2089)
b) Eichordnung (calibration rule) as of 12th August 1988 (BGBI.IS.1657) in its present version
Further information – especially regarding the addresses of the testing facilities for water meters – are given by the calibration authorities and also by the “Mess- und Eichwesen Baden-Württemberg Landesgewerbeamt – Eichdirektion – Ulmer Str. 227B, 70327 Stuttgart, Phone: (0711)-4071-233 or 4071-0
* Notice: By the modification of the calibration rule on the 24th Sept. 1992 the validity period for cold water meters has been shortened from 8 to 6 years.
Usage duration of cold and warm water meters acc. to § 77, Abs. 9 of the Eichordnung
|Year of calibration||Year of removal|
|Cold water||Warm water|